I want to continue my studies, as originally outlined, concentrating on the following question: 1. To study the nature of human cancer patients' immunological response against their tumors, accompanying progressive tumor growth and in relation to successful (or unsuccessful) therapy, such as surgery, radiation, chemotherapy, cell-mediated immunity, as detectable with microcytotoxicity and macrophage migration assays, blocking serum activity, unblocking antibodies, and cytotoxic antibodies will be studied in patients with various tumors. 2. To try clarifying, using animal model systems, to what extent it is possible to so manipulate the immune response against tumor antigens that tumor formation in vivo can be prevented and that established tumors can be arrested. The animal tumors chosen for this approach are primarily such that have "tissue-type-specific" common tumor antigens of the type seen in human neoplasms. This way it might be possible to find out whether immunity to the type of antigens characteristic of human tumors can be (made) beneficial to the host to sufficient extent to be clinically meaningful.